(1) Summary of the Invention
The present invention relates to the use of a bacteriocin in a food system to inhibit bacterial spoilage by gram positive bacteria, particularly lactobacillii. In particular, the present invention relates to the use of the bacteriocin produced by Pediococcus acidilactici NRRL-B-18050 (PAC1.0) in the system, particularly in a refrigerated salad dressing.
(2) Prior Art
The pediococci are a group of gram-positive homofermentative lactic acid bacteria which are known to produce bacteriocin, an inhibitory substance against lactic acid producing bacteria. Saprophytically these organisms are found on vegetable material (Mundt, J. O., W. G. Beattie, and F. R. Weiland, J. Bacteriol. 98:938-942 (1969)). Commercially the pediococci are important in the fermentation of vegetables, (Pederson, C. S., Bacteriol. Rev. 13:225-232 (1949)) and meats (Diebel, R. H., G. D. Wilson, and C. F. Niven, Jr., Appl. Microbiol. 9:239-243 (1961) and Smith, J. L., and S. A. Palumbo, J. Food Prot. 46:997-1006 (1983)).
The prior art has shown the presence of plasmid DNA in pediococci (Gonzalez, C. F., and B. S. Kunka, Appl. Environ. Microbiol. 46:81-89; and Gonzalez, C. F. nd B. S. Kunka, Appl. Environ. Microbiol. 51:105-109 (1986);
Daeschel, M. and T. R. Klaenhammer, Appl. Environ.
Microbiol. 50:1538-1541 (1985); Graham, D. C. and L. L. McKay, Appl. Environ. Microbiol. 50:532-534 (1985)). The prior art has also shown an association between bacteriocin and plasmid DNA in strains of Pediococcus pentosaceus and Pediococcus cerevisiae, respectively (Daeschel, M. and T. R. Klaenhammer, Appl. Environ. Microbiol. 50:1538-15 (1985); and Graham, D. C. and L. L. McKay., Appl. Environ. Microbiol. 50:532-534 (1985)). There has been no suggestion of the use of the bacteriocin in food systems by the prior art, particularly salad dressings and foods containing them.